1. Field of the Invention
The present invention relates to the technical field of sensing devices and, more particularly, to a biometric feature identification device and method.
2. Description of Related Art
With development of electronic commerce, remote payments have been developed with giant strides, and thus the commercial requirement for biometric feature identification is rapidly expanded. The biometric feature identification technologies can be divided into fingerprint identification, iris identification, DNA identification, and the like. For the efficient, safe, and non-intrusive considerations, the fingerprint identification becomes the first choice. The fingerprint identification technique includes optical, thermal sensing, ultrasonic, and capacitive approaches and, upon considering the device volume, cost, power-saving, reliability and anti-counterfeit, the capacitive approach is the most outstanding one.
Typically, the capacitive fingerprint identification can be further divided into the types of linear swiping scan and full area detection, wherein the full area detection is better due to its high resolution, efficiency, and convenience. However, due to very small sensing signal and its complicated and huge ambient noises, the full area fingerprint recognition is typically implemented by combining the sensing electrodes and sensing circuits into one IC chip using a protective sapphire film with a thickness smaller than 100 μm to protect the sensing electrodes. With such an implementation, the material cost and the packaging cost are quite high, and the product's lifetime and tolerance is unsatisfactory. Thus, the industry has attempted to increase the sensing sensitivity and the signal to noise ratio (SNR) for increasing the sensing distance between the sensing electrodes and the fingerprint to the utmost, so as to facilitate packaging the sensing IC or directly dispose the sensing electrodes under a protective glass for sensing. Furthermore, it is also desired to dispose the sensing electrodes on a substrate rather than an IC for greatly reducing the chip area, and to further integrate the sensing electrodes to the underside of the protective glass or even integrate the sensing electrodes into a display panel, so as to greatly reduce the cost and increase the product's lifetime and tolerance.
Therefore, it is desirable to provide an improved biometric feature identification device and method for mitigating and/or obviating the aforementioned problems.